A person purchasing or owning a computer made by one company, many times purchases a peripheral hardware device, such as a terminal, printer or modem, manufactured by another company. While certain industry connector standards to exist for pin assignments, such as the standard RS-232 recommended by the Electronic Industries Association, 2001 Eye Street, N.W., Washington, D.C. 20006 for the 25-pin connector being used for typical computer equipment, adherence is voluntary and the standard usually allows enough flexibility to the manufacturers that the signals provided or required on the various pins of the computer connector do not coincide exactly with the signals provided or required on the corresponding pins of the peripheral device connector. Frequently, a handshake or control signal required by the computer or peripheral device to operate will not even be provided. This means that the computer or the peripheral device will not operate if their connectors are connected directly together. The same problems are encountered when two computers or two peripheral devices are connected directly together.
In the past, the purchaser of a computer and a peripheral device with such nonmatching interconnect patterns often had to build himself, or contract for another to build, a custom or specialized interconnect cable to accomplish the proper interconnection of pins on the computer connector with the pins on the peripheral device connector so the equipment would operate together. Such specialized connect cables are expensive and time-consuming to build, especially when the manufacturer of the equipment involved does not adequately document the signals and signal requirements on the connectors used, as is frequently the case. Some manufacturers provide little, if any, such documentation; and with new models of equipment, manufacturers often take months to publish documentation with the necessary data. Additionally, manufacturers often change the interface patterns of equipment for subsequent production runs without notice or documentation.
Without an accurate specification giving the signals on particular connector pins or a schematic diagram for both the computer and peripheral device, the person building the interconnect cable must probe and search for pins that relate to each signal, and test and guess to determine which pin of the computer connector must be hard-wired through the cable to which pin of the peripheral device connector. This is a tedious trial-and-error process that requires much time, skill and good luck. A typical specialized cable may take hours or even days to complete. This process is frequently going on at the same time the equipment owner is attempting to run and debug newly purchased equipment or software which may not be operating because of problems other than incompatible connectors, making the job very difficult. The procedure typically involves soldering or otherwise connecting cable wires between various pins of the interconnect cable connectors, or use of a breakout box with jumper leads and multiple multipole switches to determine and test the proper cable configuration. As mentioned above, if either the computer or peripheral device does not supply a signal required by the other device, this must be determined and the signal generated to make the equipment operate together.
For a few of the more popular computers and peripheral devices, the necessary interconnect cables are manufactured in advance and available for purchase, but the combinations of equipment for which such prefabricated cables are available are extremely limited, the supplies are often scarce, and not all sellers of computers and peripheral devices stock the needed cables. The prefabricated cables are relatively few in number compared to the number of equipment combinations possible with incompatible connectors, a result of the fact that numerous computers and peripheral devices exist which are manufactured by many different manufacturers. Almost each combination of equipment will require a different specialized interconnect cable. Of course, once a specialized cable is purchased or built for a particular computer and peripheral device, it has the further disadvantage of not being usable with another peripheral device the computer user may purchase in the future, thus requiring another specialized cable.
It will therefore be appreciated that there has been a significant need for a relatively inexpensive and easy to use interface cable assembly which will quickly and properly interconnect most computers and peripheral devices with nonmatching interconnect patterns without requiring knowledge of the particular pin or signal configuration of either the computer or peripheral device. Preferably, the interface cable assembly should not require external power to operate, should provide any missing and necessary handshake or control signals, should provide means for determining whether the particular computer and peripheral device to which it is connected is in a data transmit and receive mode, and should provide means to assist the user in setting the various switches and parameters of the computer and peripheral device to make the equipment function when properly interconnected. The present invention fulfills this need, and further provides other related advantages.